Car haul



Jan. 26, 1960 w. J. HEAcocK CAR HAUL s Sheets-Sheet 1' Filed Oct. 25,1956 Jan. 26, 1960 -w. J. HEAcocK 2,922,625

CAR HAUL v Filed Oct. 25, 1956 3 Sheets-Sheet 2 w. J. HEAcocK Jan. 26,19-60 CAR HAUL 3 Slieets-Sheet 3 Filed Oct. 25, 1956 United StatesPatent CAR HAUL Ward J. Heacock, Chicago, Ill., assignor to Link-BeltCompany, a corporation of Illinois Application October 25, 1956, SerialNo. 618,270

, 4 Claims. (Cl. 254-185) This invention relates to new and usefulimprovements in car hauls and deals more particularly with apparatus fordriving traction cables'that are employed for hauling cars and the like.

Car hauls employing traction cables have, in the past, been arranged sothat the cable formed a loop with one run extending along the section oftrack over which the cars were to be hauled. Opposite end portions ofthe looped cable were wound in opposite directionsaround two drumssupported on a single shaft so that the opposite end portions of thecable were simultaneously wound onto and off of their respective drums.In this type of installation, elaborate and costly take-up devices werenecessary to compensate-for stretching of the cable and for thedifferences in the winding and unwinding rates as the diameters of theturns of the cable on the drums varied in inverse relationship. Further,the loop of the cable was always under tension and, therefore, subjectto damage by impact with falling or moving objects.

Other known types of car hauls have employed two separately supportedand independently rotated drums for alternately winding in one endportion of a looped traction' cable on its drum while a brake resistedrotation of the other drum to maintain proper cable tension. In thistype of installation a mechanical clutch was required to drivinglyconnect the prime mover to the drum selected for rotation and both theclutch and brakewere subjected to excessive wear so that constantmaintenance and frequent repairs were necessary.

The primary object of this invention is to provide a device for drivingthe traction cable of a car haul alternately in opposite directionswhile the prime mover of the driving device operates continuously in asingle direction.

Another important object of this invention is to provide a device fordriving the traction cable of the car haul alternately in oppositedirections with the cable being maintained under proper tension duringoperation of the drive and with the tension on the cable being releasedwhen movement of the cable stops.

A further important object of the invention is to provide a device fordriving the traction cable of the car haul in such a manner that theforce transmitted by the cable may be both varied and reversed indirection and with the cable being maintained under proper tensionduring the driving operation.

Still another object of the invention is to provide a device for drivinga traction cable alternately in opposite directions with the drivebetween the prime mover of the device and the cable including anelectrical coupling which permits application of the driving or brakingforce to the cable without frictional or positive engagement between theportions of the coupling.

Other objects and advantages of the invention will be apparent duringthe course of the following description.

In the accompanying drawings forming a part of this specification and inwhich like reference characters are employed to designate like partsthroughout the same,

2,922,625 Patented J an. 26, 1 960 lice Figure 1 is a schematic view ofa car haul installation embodying the invention and employed for movingcars in opposite directions along either of two parallel track sections,

Figure 2 is a schematic view of a modified car haul installationembodying the invention and employed for moving cars in either directionalong a single track section, Figure 3 is a top plan view of the driveemployed in the car hauls of Figs. 1 and 2,

Figure 4 is an end elevational view of the drive illus trated in Fig. 3,and

Figure 5 is a side elevational view, partly in cross section, of thedrive of Figs. 3 and 4, and adiagrammatic view of the electrical systemfor controlling operation of the drive. a

In the drawings, wherein for the purposeof illustration is shown thepreferred embodiment of the invention,-and first particularly referringto Fig. 1, there is shown a pair of spaced parallel track sections 6 and7 over which cars 8 are to be moved. In this installation, the cars 8may bemoved in either direction along either of the two track.

sections by the single traction cable 9. The opposite end portions ofthe traction cable 9 are wrapped around drums 10 and 11 and the cableextends from the drums through an elongated loop which is positionedbetween the two track sections 6 and 7 and has its closed portionsupported by a pulley 12. Draft devices 13 are employed for detachablyconnecting the cars 8 to the adjacent sides of the loop in the tractioncable 9 so that alternate rotation of the drums 10 and 11 to wind intheir associated; end portions of the cable will cause the two sides ofthe loop and any cars that are connected thereto to be moved alternatelyin opposite directions along the track section 6' and 7. The drive foralternately rotating the drums 10 and 11 and the controls for the drivewill be later described.

The car haul illustrated in Fig. 2 is employed for moving cars 14alternately in opposite directions along a single track section 15 bymeans of draft devices 16 which from the loop to the'drums 10 and 11around which the.

opposite end portions of the cable are wrapped. The drums 10 and 11 andthe drive for rotating the drums along with its controls are identicalto those illustrated in Fig. 1 and the following description thereof isequally applicable to the car hauls of both Figs. 1 and 2. 7

Referring now to Figs. 3 and 4 for a detail description of the drums 10and 11 and the manner in which they;

are mounted for independent rotation, it will be seen thatthe drums aresupported on a base 20 formed of suitably arranged structural membersand rigidlyconnected to a;

foundation 21 by anchor bolts 22, or the like, as illustrated in Fig. 4.Each of the drums 10 and 11 is rigidly mounted on a shaft 23 and the twoshafts are axially aligned and have their opposite end, portionssupported on the base 20 by bearings 24. v

' Between the outer end of the drum 10 and the adjacent bearing 24 thereis provided a gear 25 which is rigidly connected to the drum forrotating the latter. A gear 26 is similarly mounted at the outer end ofthe drum 11 for rotating the latter. Y

' At the outer end of the shaft 23 of the drum 10, there is provided asmall sprocket 27 which is connected by a chain 28 to the sprocket 29 ofa limit switch 30. A;

second sprocket 27 is similarlymounted on the shaft'ofthe drum 11 andconnected by a chain 28 to the sprocket for rotation:

asaaeas sprocket 29 associated with each shaft 23 are enclosed by aguard 32. Each of the two limit switches 30 and 31 is of the type whichis closed by any rotation of. its sprocket 29 away from a given positionand will remain closed until the direction and number of subsequentrotations have returned the sprocket to its initial position. In otherwords, the limit switches 30 and 31 may be adjusted to openwhen thedrums and '11, respectively,

have been rotated to wind a selected amount of cable onto or off of thedrum. The manner in which the limit switches 30 and 31 are connectedinto the electrical circuit for controlling the operation of the drivefor rotating the drums 10 and 11 will be later described.

At one side of the base there is provided an elongated platform 33 whichserves as a base for the various components of the drive for rotatingthe drums 10 and 11'. Mounted on the platform 33 with its axis inparallel relationship with the axes of the shafts 23 is a drivemotor 34having its drive shaft 35 extending from the opposite ends thereof.

One end of the drive shaft 35 is connected through a flexible coupling36 to the input shaft of an electromag netic coupling 37, which will belater described. The output shaft of the coupling 37 is connectedthrough a flexible coupling-38 to the input shaft of a gear reductionunit 39 atone end of the platform 33. The output shaft 41 of the gearreduction unit 39 has its outer end portion supported by a bearing 42and a spur gear 43 is keyed to this output shaft in meshing engagementwith the gear that is rigidlyconnected to the drum 10 The opposite endof the drive shaft is similarly connected through a flexible coupling44, electromagnetic coupling 45, flexiblecoupling 46, gear reductionunit 47, and spur gear 48 to the gear 26 associated with the drum 11.The gear 48 is mounted on the output shaft 49 of the gear reduction unit47 and the outer end of the output shaft is rotatably supported bya'bearing 51.

Referring now to Fig. 5 for a detail description of the electromagneticcouplings 37 and 45, it will be seenfthat they are of identicalconstruction so that the following description of the coupling 37 isequally applicable to the coupling and like reference characters havebeen applied to the corresponding parts of each. A coupling housing 52rotatably supports the input and output shafts 53 and 54, respectively,in axial alignment and with their inner ends in closely spacedrelationship with each other. Rigidly mounted on the inner end of theinput shaft 53 is-an open-ended drum 55, the inner cylindrical surfaceof which surrounds and is spaced radially from the adjacent end portionof the output shaft 54. Keyed to the inner end portion of the outputshaft 54 is a field assembly 56 which includes a suitably constructedcore 57 and a field coil 58'. The periphery of the field assembly 56lies in closely spaced relationship with the inner cylindrical surfaceof the drum but is separated therefrom by a uniformclearance or air gapso that the drum and field assembly are free to rotate independently ofeach other when no current is supplied to the field assembly. Electriccurrent isconducted to the field coil 58 of the field assembly 56through brushes 59 and 60 which contact slip rings 61 and 62,respectively, that are mounted on the output shaft 54 and rotate withthe field assembly.

- When the field coil 58 is energized, the core 57 becomes a magnet andthe magnetic lines of force established in the core will flow betweenthe north and south poles of the field assembly through the adjacentportion of the drum. Relative rotation between the drum 55 and fieldassembly 56, therefore, will cause these magnetic lines offorceto besheared in the air gap between'the drum and field assembly and eddycurrents will be generated in theportion ofthe: drum adjacent the field,assembly. These induced eddy currents develop a second magnetic fieldwhich has an attraction to the magnetic field of the fi'eld assembly 56'and will cause the field assembly to rotate with the drum 55, totransmit torque from the input shaft 53 to the output shaft 54. Theamount of the torque delivered to the input shaft 53 that is transmittedto the output shaft 54 will vary in accordance with the magnitude of theeddy current field in the drum 55 which in turn varies in accordancewith the strength of the magnetic field in the field assembly 56 andwith the slip or difference in speeds between the drum and the fieldassembly. In other words, the torque delivered by the output shaft 54may be varied without changing the operation of the motor 34 byincreasing or decreasing the current supplied to the field coil 58through the brushes 59 and 68. Of course, when no current is supplied tothe field coil 58, no torque will be transmitted by the output shaft 54despite the continued rotation of the drum 55 by the motor 34.

As illustrated in Fig. 5, current for energizing the two couplings 37and 45 is supplied through lines L1 and L2 which lead to a source ofsupply of electrical energy, not shown. The line L2 is connecteddirectly to the brush 60 of each of the two couplings 37 and 45 bybranch lines a and b, respectively. The supply of current from directionfrom its 01f position to a low position and is further movable past eachof the two low positions to a high position as illustrated in Fig. 5.

The low and high positions on one side of the off position have beenarbitrarily designated as reverse positions and the high and lowpositions on the opposite side of the off position as forward positionsto simplify the subsequent description of the movement imparted to thecables 9 by movement of the drum actuator D to its various positions.

Mounted on the drum actuator D are a plurality of. actuating devices Xforengaging and operating the contactors C1 to C5, inclusive. Theactuatingdevices X in circumferential alignment with contactor C1 arearranged to open the normally closed contactor in all positions of thedrum actuator except the OE position. Arranged in circumferentialalignment with the contactor C2 is am actuating device X which willengage and close the con-l tactor C2 only when the drum is in the highposition on the forward side of its off position. The contactor C3 willbe closed by actuating devices X on the drum actuator D. when the latteris in either its low or its high position on the forward side of its offposition. The contactor C4 will be closed by an actuating device X onthe drum actuator D when the latter is in its high position on thereverse side of the off position and the contactor C5 will be closed byactuating devices X on the drum actuator D when the latter is in eitherits low or its high position on the reverse side of the off position.

The line L1 is connected by branch lines c, d and e to one side of thecontactors C1, C3 and C5, respectively. The opposite side of thecontactor C1. is connected by a. line f to the coil E of a conventionaltiming relay R and by a branch line g to one side of the switch Soperated by the coil E. The circuit through the coil E is completed by aline it which leads to the line L2. The other terminal of the switch Sis connected through a line i andv a; resistor r1 to the center tap of aresistor r2 the end taps of which are connected by lines 1' and k to thebrushes 59 of the couplings 3'7 and 45.

The side of the contactor C3 opposite to the branch lined is connectedby a line In to one side of the limit switch 30 and the opposite side ofthe limit switch 36 is connected by' a line n through a resistor r3 tothe wire 1';

The side of the contactor C5 opposite its connection i the branchli'ne,e is connectedby a line 0 to. one side of the limit switch 31 and theopposite side of the limit Switch is connected by line p through theresistor r4 to the linek.

The opposite-sides of the contactor C2 are connected by lines q and sand to the line n on opposite sides of the resistor r3 so that the linesq and s form a bypass circuit around the resistor when the contactor C2is closed. The contactor C4 is similarly connected by lines t and u tothe line on opposite sides of the resistor r4 to form a by-pass circuitaround the resistor when the contactor C4 is closed.

The operation of the circuit described above in controlling the amountof torque transmitted by the couplings 37 and 45 and the direction ofmovement imparted to the cable 9 thereby will be described as follows:

Referring to Fig. 1, it will be readily apparent that the opposite sidesof the loop in the cable 9 adjacent the two track sections 6 and 7 willbe moved alternately in opposite directions and will impartcorresponding movements to any cars 8 connected thereto when the drums10 and 11 are alternately rotated to wind the cable thereon. Of course,when the cable is being wound onto either of the two drums 10 or 11, acorresponding amount of cable must be unwound from the other drum.Further, if the drum 10 or 11 from which the cable is being unwound isrestrained or retarded in its rotation, the cable 9 will be maintainedin proper tension to prevent overhauling of the cable by the moving cars8.

By reference to Fig. 2, it will be readily apparent that the side of theloop in the cable 17 adjacent the track section 15 will be movedalternately in opposite directions and will impart similar movements toany cars 14 connected thereto by alternate rotation of the drums 10 and11 in the same manner as was described in connection with Fig. 1.

Before describing the operation of the drive for .actuating the twodrums 10 and 11, it will be noted that the motion produced in the cable9 when it is wound onto the drum 10 and unwound from the drum 11 isarbitrarily designated as being a forward movement, and the movement ofthe cable in the opposite direction by being wound onto the drum 11 andunwound from the drum 10 has been designated a reverse movement. It willalso be noted that because the two end portions of the cable 9 are woundaround the drums 10 and 11 in the same direction, the two drums must berotated in the same direction to wind cable thereon or, stated in adifierent manner, the two drums must be rotated in opposite directionswhen the cable is wound onto one drum and off of the other drum.

Before describing the operation of the drive for rotating the drums 10and 11, it will be noted that the motor 34 is continuously operated in adirection to produce a torque which, when transmitted to the two drums,will tend to rotate both of them in the same direction to wind theassociated portions of the cable 9 thereon. With the drum actuator D inits off position, as illustrated in Fig. 5, the contactor C1 will beclosed and the remaining contactors C2 to C5, inclusive, will be open.Also, the timing relay R will have opened the switch S so that nocurrent will flow through the field coil 58 of either the coupling 37 orthe coupling 45. The drums 55 of the two couplings, therefore, will berotating entirely independently of their associated field assemblies 56and no torque will be transmitted from the motor to either of the twodrums 10 or 11.

Assuming then that motion is to be imparted to the cable 9 in a forwarddirection, the drum actuator D is moved to the low" position on theforward side of the o position. In this position, the contactor C1 willbe opened and the contactor C3 closed. The remaining contactors C2, C4and C will remain in their open positions. Current will thereupon flowfrom the line L1 through the branch line d, contactor C3, line m, limitswitch 30, line n, resistor r3 and line j to the brush 59 of thecoupling 37 and from the brush of the coupling through line a to theline L2 so that a circuit is closed through the field coil 58 of thiscoupling. A

much smaller current will also flow from the line 1' through theresistor r2 and line k to the brush 59 of the coupling 45 and from thebrush of this coupling through the line b to line L2 so that a circuitis closed through the field coil 58 of the coupling 45 when the coupling37 is energized. Since the current fiowing to the field coil 58 of thecoupling 37 exceeds that flowing to the field coil 58 of the coupling45, the torque transmitted by the coupling 37 will exceed thattransmitted by the coupling 45 and will be transmitted through the gearreduction unit 39 and gears 43 and 25 to rotate the drum 10 in adirection to wind the cable 9 thereon. The lower torque transmittedthrough the coupling 45, however, will be transmitted through the gearreduction unit 47 and gears 48 and 26 to apply a torque to the drum 10in a direction to cause this drum to resist the unwinding of the cable 9therefrom. This resistance to the unwinding will cause the cable 9 to bemaintained under tension during movement thereof in a forward direction.

If the torque transmitted to the drum 10 by movement of the drumactuator D to the low position on the forward side of the off positionis insufi'icient, a higher torque may be transmitted by movement of thedrum actuator to the high position on the forward side of the offposition. In this position of the drum actuator D, the contactors C1 andC3 will remain in their open and closed positions, respectively, thecontactor C2 will be closed and the contactors C4 and C5 will remainopen. The closing of the contactor C2 closes a by-pass circuit throughthe lines q and s around the resistor r3 to increase the flow of currentto the brush 59 of the coupling 37 and to thereby increase the torquetransmitted by this coupling.

When sufficient forward movement has been imparted to the cable 9 toaccomplish the desired movement of the cars attached thereto, the drumactuator D is returned to its 0 position at which time the contactor C1will be closed and the remaining contactors C2 to C5, inclusive, will beopened. The closing of the contactor C1 will permit current to flowthrough the branch line c and the line 1 to the coil E of the timingrelay R, the opposite side of the coil being connected by the line It tothe line L2. The timing relay R will thereupon immediately close theswitch S to permit the flow of current through the lines c, f, i and theresistor r1 to the center tap of the resistor r2 and in oppositedirections through the resistor r2 to the wires 1' and k and to thebrushes 59 of the couplings 37 and 45, respectively. This equal flow ofcurrent to the field coils 58 of the two couplings 37 and 45 will causethe latter to transmit equal torques to their associated drums 10 and 11to apply a braking action against further movement of the cable 9. Aftera predetermined time interval during which movement of the cable 9 willstop, the timing relay R will open the switch S to stop all flow ofcurrent to the two couplings 37 and 45 so that no torque will betransmitted to either of the drums 10 or 11. These drums then will befree to riotate so as to release the tension on the cable 9 so that anyobjects falling onto the cable, or colliding therewith, will not damagethe cable or any of the drive components.

During the above described forward movement of the cable 9, thesprockets 29 of the two limit switches 30 and 31 will be rotated bytheir associated sprockets 27 and chains 28. The limit switch 30,therefore, may be adjusted so that forward movement of the cable 9 to adesired limit will cause the limit switch 30 to be opened to prevent anyfurther flow of current to either of the two couplings 37 or 45.

If the cable 9 is to be moved in a reverse direction,

the drum actuator D is moved to the low position on the; reverse sideof.the off position at which time. the contactor C1; is opened and thecontactor C is closed, the remaining contactors C2,. C3 and C4 remainingin; their open positions. Current will thereupon flow through. the linese and 0, limit switch 31, line 1'' and resistor r4 to the brush 59 ofthe coupling 45. A smaller current will also flow from the line pthrough the line k, resistor r2 and line i to the brush 59 of thecoupling 37. The greater torque transmitted to the drum 11 through thecoupling 45 will thereupon cause the drum 11 to wind in the cable 9. Atthe same time, the cable will be unwound from the drum against thelesser torque transmitted thereto through the coupling 37.

If a greater torque is required, the drum actuator D may be moved to itshigh" position on the reverse side of the cit position. In thisposition, the contactors C1 and C5 will. remain in their open and closedpositions, respectively, the cont-actor C4 will be closed and thecontractors C2 and C3 will remain in their open positions. A by-passcircuit is thereby closed through the lines 2 and 1: around the resistorr4 so that a greater current will flow to the brush 59 of the coupling45 to. increase the torque transmitted by this coupling.

When the drum actuator D is returned to its off position, the contactorC1 will again be closed and the remaining contactors C2 to C5,inclusive, .will be opened so that the timing relay R will again closethe switch S to apply equal currents to the two couplings 37 and 45 soasto equalize the torques transmitted by the couplings. This applies abraking action on the movement of the cable 9. Subsequent reopening ofthe switch S will again release the drums 10 and 11 for sufficientmovement to relieve the tension in the cables 9.

Rotation of the sprocket 29 for the limit switch 31 during reversemovement of the cable 9 will open the limit switch 31 at a desiredlimit.

The above described drive for the cable 9 provides.

for its alternate movement in opposite directions and for braking actionagainst further movement of the cable by movement of the drum actuator Dto the various positions described, and, by means of the limit switches30 and 31, prevents excessive movement of the cable in either a forwardor a reverse direction. Further, it will be noted that no frictionallyengaged parts are employed' for the transmission of torque to or theapplication of a braking efiect on the drums 10 or 11 so thatmaintenance and replacement of parts is maintained at a minimum.

It is to be understood that the form of this invention herewith shownand described is to be taken as a' preferred example of the same, andthat various changes in the shape, size and arrangement of parts mayberesorted' to without departing from the spirit 'of the invention orthe scope of the subjoined claims.

Having thus described the invention, I claim:

1. In a traction cable drive including a pair of drums supported forindependent rotation with each having anassociated end portion of thecable woundthereon, a

prime mover, and an electromagnetic coupling associated with each ofsaid drums for drivingly connecting said prime mover to each drum torotate the latter in a dimotion to wind in the end portion of the cableassociated therewith and for transmitting varying amounts of torquethereto in response to variations in the electrical energy supplied tothe respective coupling, the improvement which comprises control meansactuatable at the will of the operator to electrically energize saidcouplings, and means operable upon deactuation of said control means bythe operator to initially energize each of said couplings withsubstantially equal amounts of electrical energy to stop the rotation ofsaid drums through oppositely directed tension forces applied to saidcable and to subsequentlydeenergize said. couplings after the lapseof a;pres determined. time.- to stopthe transmission ofv torque; to. said:drums and release the tension in said traction cable ,,said controlmeans comprising a separate circuit for supplying electrical energy tothe coupling associated with-each drum, a. branch circuit having anelectrical resistance therein extending between said separate circuitsfor supplying a restricted amount of electrical energy from eitherseparate circuit to the coupling associated with. the other separatecircuit, and switch means operable to alternately close a selected oneof said separate circuits.

2. The improvement as. defined in claim 1 wherein each of said separatecircuits has a limit switch. connected therein, and including means.associated with each of said drums for operating. each of said limitswitches to open the separate circuit associated therewith when thecoupling supplied with electrical energy by the circuit has rotated itsdrum to wind av predetermined length of cable. thereon.

3. The improvement as defined in claim 1 wherein each of said separatecircuits has an electrical resistancetherein between said. switch meansand said branch circuit, a by-pass circuit arranged in parallelrelationship with the resistance of each separate circuit, and switchmeans operable to close each of said by-pass circuitsv when theassociated separate circuit is closed.

4. In a traction cable drive including apair. of drums supported forindependent rotation with each having an associated end portion of thecable wound thereon, a prime mover, and an electromagnetic coupling.associated with each of said drums for drivingly connecting said primemover to each. drum to rotate the latter in a direction to wind in theend portion of the cable associated therewith and for: transmittingvarying amounts of torque thereto in response to variations in theelectrical energy. supplied. to the respective coupling, the improvementwhich comprises control means for electrically energizing saidcouplings, and additional means operable upon actuation' thereof. toinitially energize each of said couplings with substantially equalamounts of electrical energy to stop the rotation of said drums throughoppositely directed tension forces applied to said. cable and forsubsequently deenergizing said couplings at a predetermined time aftersaid actuation to stop the transmission of torque to said drums and.release thetension in said cable, said control means including amultiple position switch movable to different positions for causing thetorque transmitted by one coupling to exceed the. torque transmitted bythe other coupling and movable to a further position for actuating saidadditional means.

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